Resolved I saw error logs in the web logs for the first time,after updating "Plesk18.0.34Update2".

[yaswaka]

For example:
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[Wed Apr 07 11:04:47.536071 2021] [proxy_fcgi:error] [pid 8295:tid 140088344311552] [client ***.***.***.***:45130] AH01068: Got bogus version 51, referer:

[Wed Apr 07 11:04:47.536196 2021][proxy_fcgi:error] [pid 8295:tid 140088344311552] (22)Invalid argument: [client ***.***.***.***:45130] AH01075: Error dispatching request to :, referer:
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I 've not seen thease logs for not "Plesk18.0.34Update2".
I don't have many error logs like this.
I would like to know what the solution is.

CentOS7
Plesk18.0.34Update2

 

[IgorG]

I hope this KB article will help: A website hosted in Plesk contains the error in its log: AH01068: Got bogus version

 

[yaswaka]

I understand.